Universal software for data assimilation: variational method for global oceans

Principal Investigator

Dr Thierry Morel
Global Change and Climate Modelling Team
CERFACS
42 av. G. Coriolis
31057 Toulouse Cedex 1
France

morel@cerfacs.fr

Project description

The PALM project (Projet d'Assilmilation par Logiciel Multi-methodes) was first design to support the French oceanography project MERCATOR whose aim is to achieve an operational high resolution ocean forecasting system.

It aims to implement a general tool allowing to easily integrate high performance computing applications in a flexible and extensible way. Its application domain extends to every kind of scientific applications.

In the framework of PALM, applications are split in elementary components that can exchange data. The main future of the PALM coupler are the dynamic launching of the coupled components, the full independence of the components from the algorithm, the parallel data exchanges with automatic redistribution and the separation of the physics from the algebraic manipulations performed by the PALM algebra toolbox.

The main releases of the PALM software (http://www.cerfacs.fr/globc/PALM_WEB/) are called PALM_RESEARCH and PALM_MP. The PALM softwares are provided with both an installation and a user guide in order to facilitate the installation and the use of PALM as well as a tutorial which gradually introduces the concepts, fonctionalities and use of the PALM softwares. Moreover, three days training sessions are regularly organized at CERFACS and a support is available for users (palmhelp@cerfacs.fr).

PALM_RESEARCH (Fortran 90 programming, based on SPMD concept and the MPI1 message passing library) initially developed in order to fill the MERCATOR project needs was delivered to this team at the end of 2001.

PALM_MP (C and Fortran 90 programming, based on MPMD concept and the MPI2 message passing library) provides communications between independant processes. On the contrary to the MPI1 standard, the MPI2 one allows a better memory management and leads an higher and clearer independence between sources which have to be coupled. MPI2 is now available on the most common platforms. The main PALM_MP new features are the introduction of the sub-object concept which allows to pick up only a part of an object, the possibility for the users to use C/C++ languages as well as FORTRAN77 and 90 to develop their own PALM units, more flexible temporal management of objects, real-time supervision and parallel algebra toolbox. The current version of PALM_MP is now PALM_MP_2_2_0.

For more informations about the PALM software, please refer to the web site http://www.cerfacs.fr/globc/PALM_WEB/

For more details, please refer to the latest progress report.

Additional information

Project started in 1997 - will finish 2007.